UltraDefrag is powerful Open Source defragmentation tool for Windows. It's engine is very fast, because it is created as kernel-mode driver. They are three interfaces to them: graphical, console and native. First is very useful, because it use cluster map visualization. Console is good for task scheduler, and native tool – for advanced users and programmers. Design of the UltraDefrag is very ergonomic: no skins, no localization, no animation and so on. It’s true small and powerful program! It can be used on Windows 2000, Windows XP, Windows Server 2003 and Windows Vista.

Features and restrictions:

optimal algorithm

support basic include/exclude filters

exclude zero-length files and files that are placed in MFT

full support of compressed files processing

'Compact' command optimize free space disposition

generate useful html report

don't support volumes with more than 4.294.967.295 clusters

very fast defragmentation, because engine is kernel mode driver and has optimal algorithm.